TLS Proxy Best Practice
draft-wang-tls-proxy-best-practice-00

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OPSEC Working Group                                              E. Wang
Internet-Draft                                                A. Ossipov
Intended status: Informational                       Cisco Systems, Inc.
Expires: May 7, 2020                                           R. DuToit
                                                                Symantec
                                                       November 04, 2019

                        TLS Proxy Best Practice
                 draft-wang-tls-proxy-best-practice-00

Abstract

   TLS proxies are widely deployed by organizations to enable security
   features and apply enterprise policies.  This document defines a TLS
   proxy and discusses a wide range of security requirements to guide
   TLS proxy implementations.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on May 7, 2020.

Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   include Simplified BSD License text as described in Section 4.e of

Wang, et al.               Expires May 7, 2020                  [Page 1]
Internet-Draft                   tlsp-bp                   November 2019

   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions and Definitions . . . . . . . . . . . . . . . . .   4
   3.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  Security and Privacy Requirements . . . . . . . . . . . . . .   4
     4.1.  Securely provision within the administrative domain . . .   4
     4.2.  Maintain security posture and limit modifications . . . .   5
     4.3.  Be secure by default  . . . . . . . . . . . . . . . . . .   6
     4.4.  Use independent key material  . . . . . . . . . . . . . .   6
     4.5.  Protect against known vulnerabilities . . . . . . . . . .   6
     4.6.  Detect and propagate protocol version downgrade markers .   7
     4.7.  Implement special measures to handle session resumption .   7
     4.8.  Adapt to protocol changes . . . . . . . . . . . . . . . .   8
     4.9.  Respect regulations and privacy . . . . . . . . . . . . .   8
     4.10. Respect sensitivity of decrypted payload  . . . . . . . .   8
     4.11. Enforce certificate validation standards  . . . . . . . .   8
     4.12. Provide a secure operating environment  . . . . . . . . .   9
   5.  Usability and Functional Requirements . . . . . . . . . . . .   9
     5.1.  Provide the ability to enforce policy without intercept .   9
     5.2.  Selectively decrypt based on policy . . . . . . . . . . .  10
     5.3.  Limit performance impact  . . . . . . . . . . . . . . . .  11
   6.  Security & Privacy Considerations . . . . . . . . . . . . . .  11
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  12
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  13
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

   A TLS proxy refers to a set of network functions and products that
   intercept TLS sessions per an organizational security policy.  A TLS
   proxy is deployed between endpoints such as TLS clients and servers.
   Based on an organizational policy, it may proxy a TLS handshake by
   terminating it on the client side and starting a new handshake with
   the server.  As a result, the TLS proxy is able to decrypt the
   traffic from each side of the TLS session for various purposes, and
   then optionally re-encrypt the traffic before forwarding it to the
   other side of the session.  A TLS proxy may leverage the session